Fraud from ATT?

Hello, I have called many times in the last few months trying to get answers here so if you could help me that would be great. #1: My business line is being forwarded to another person (I think a VoIP service). ATT tells me it’s my voicemail but it’s not. I’ll have my phone in front of me and have someone call me and it goes straight to vm without ever showing a missed call on my end. #2. What is a voicemail pilot number? And if ATT is correct in saying the forwarding should be my voicemail then why are those 2 numbers different (by one digit). And this happened on my personal line and my business line. I highly doubt that would even be possible by an “error”, on 2 accounts opened entirely different years and locations etc. can someone please help me? It’s taken months, maybe 10 falls, and still no answers.